The explosion, on Tuesday afternoon, was in Zhongshan park, next to the compound where China's leaders live and work and across the road from Tiananmen Square. Yesterday news managers had things under control: cleaners and ticket-sellers who had been in the park swore they had heard and noticed nothing at the time of the blast. China normally puts a news clamp on sensitive events but traffic disruption during Tuesday's rush-hour meant people must have known something had happened. Yesterday's Peking Daily said a Hunan man had committed suicide.
China's leaders are particularly concerned that no such incidents take place in the run-up to the return of Hong Kong on 1 July. Security has already been tightened since 7 March, when a bus bomb exploded in a shopping street.
No one has been arrested over that crime or other explosions in Peking around the time, though suspicions centred on Muslim separatists from Xinjiang province, western China, or state-enterprise workers who have lost their jobs.
Mystery still surrounds a bus blast on Monday in Shunde, Guangdong province, in which a young couple set off a bomb, killing themselves and three others. Explosions on buses and trains regularly take place in China because people are illegally transporting explosives, which are easily obtainable in a country with a vast network of public and private mines.